WO2016072792A1 - Method and apparatus for stopping and restarting mbms service - Google Patents

Abstract

Provided are a method and an apparatus for stopping and restarting an MBMS service in a wireless communication system. A terminal receives multicast channel (MCH) scheduling information (MSI) and checks whether a special value is included in the received MSI. If the special value is included in the MSI, then whether to stop or suspend the MBMS service can be determined. That is, MSI can be considered in stopping the MBMS service. Furthermore, stopping is terminating an MBMS service without a consideration for restarting same, and suspending is terminating an MBMS service with a consideration for restarting same.

Description

Method and device for suspending and resuming MBMS services

The present invention relates to mobile communication, and more particularly, to a method and apparatus for stopping and resuming a multimedia broadcast / multicast service (MBMS) service.

MBMS (Multimedia Broadcast / Multicast Service) is a service that transmits data packets to multiple users at the same time similarly to the existing CBS (Cell Broadcast Service). However, while CBS is a low-speed message-based service, MBMS is intended for high-speed multimedia data transmission. In addition, CBS is not based on IP (internet protocol), but MBMS is based on IP multicast. According to the MBMS, when a certain level of users exist in the same cell, the users can receive the same multimedia data using a shared resource (or channel), thereby increasing the efficiency of radio resources and allowing users to value multimedia services. It is available cheaply.

MBMS uses a shared channel to efficiently receive data from a plurality of terminals in one service. For one service data, the base station does not allocate a dedicated channel as many as the number of terminals to receive the service in one cell, but allocates only one shared channel. In addition, since a plurality of terminals simultaneously receive the shared channel, the efficiency of radio resources is increased. In relation to the MBMS, the terminal may receive the MBMS after receiving system information about the corresponding cell.

The present invention proposes a method and apparatus for stopping an MBMS service. The present invention also proposes a method and apparatus for resuming a suspended MBMS service.

The UE may receive Multicast Channel Scheduling Information (MCH Scheduling Information) and check whether a special value is included in the received MSI. If the special value is included, the MBMS service can be stopped.

If the MBMS service stops (Stop), the UE may release the MRB and establish a unicast bearer, in which case it does not monitor the MSI, MTCH or MCCH.

When the MBMS service is suspended, the UE may establish a unicast bearer without releasing the MRB. In this case, the UE continuously establishes the monitoring of the MSI or the MTCH, and if any one is monitored, the MBMS is suspended through the MRB. MBMS service can be resumed.

In one embodiment, a method of suspending and resuming an MBMS service in a wireless communication system is provided. The UE receives MSI (MCH Scheduling Information), checks whether a special value is included in the received MSI, and if the special value is included in the MSI, Determining whether to stop or suspend. However, the interruption of the MBMS service is an interruption of the MBMS service not considering resumption of the MBMS service, and the suspension of the MBMS service is an interruption of the MBMS service considering the restart of the MBMS service.

If the terminal decides to stop the MBMS service, the terminal may further include releasing an MRB (radio bearer for MBMS). The terminal may further include stopping the monitoring of the MSI, MTCH or MCCH. When the terminal is in the RRC_IDLE state, the method may further include stopping prioritization of the MBMS frequency of interest. The terminal may further comprise establishing a unicast bearer. The terminal may further include indicating that the user is not interested in the MBMSInterestIndication message.

When determining to suspend the MBMS service, the terminal may further include maintaining an MRB (radio bearer for MBMS). The terminal may further include continuing to monitor the MSI, MTCH or MCCH. If at least one of the MSI or the MTCH is monitored, the method may further include resuming the MBMS service suspended through the MRB. The terminal may further comprise continuing to prioritize the MBMS frequency of interest. The terminal may further comprise establishing a unicast bearer.

In another embodiment, a terminal for suspending and resuming an MBMS service in a wireless communication system is provided. Memory; Transceiver; And a processor connecting the memory and the transceiver, wherein the processor controls the transceiver to receive Multicast Channel Scheduling Information (MCH Scheduling Information) and includes a special value in the received MSI. If the MSI includes the special value, it may be configured to determine whether to stop or suspend the MBMS service. However, the interruption of the MBMS service is an interruption of the MBMS service not considering resumption of the MBMS service, and the suspension of the MBMS service is an interruption of the MBMS service considering the restart of the MBMS service.

The processor may be configured to release an MRB (radio bearer for MBMS) if it decides to stop the MBMS service.

The processor may be configured to maintain an MRB (radio bearer for MBMS) if it decides to suspend the MBMS service. The processor may be configured to continue monitoring the MSI, MTCH or MCCH. The processor may be configured to resume the MBMS service suspended through the MRB when at least one of the MSI or the MTCH is monitored.

According to the present invention, it is possible to reduce the time for the terminal to recognize the interruption of the MBMS service.

1 shows a wireless communication system to which the present invention is applied.

2 shows a network structure for MBMS to which the present invention is applied.

3 shows a user plane structure for MBMS support.

4 shows a control plane structure for MBMS support.

5 shows the operation of the terminal in the RRC idle state.

6 shows a process of establishing an RRC connection.

7 shows an RRC connection resetting process.

8 shows an RRC connection reestablishment procedure.

9 shows the structure of an MBSFN subframe.

10 shows an example of an MBSFN subframe configuration for performing an MBMS service.

11 illustrates a method of notifying the terminal of the change of MCCH information when the MCCH information is changed.

12 shows the expanded MSI.

FIG. 13 is a block diagram illustrating a case in which a special value of an MSI is considered for MBMS service stop or suspension in accordance with an embodiment of the present invention.

14 is a diagram illustrating a wireless communication system in which an embodiment of the present invention is implemented.

The following techniques include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and the like. It can be used in various wireless communication systems. CDMA may be implemented by a radio technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be implemented with wireless technologies such as global system for mobile communications (GSM) / general packet radio service (GPRS) / enhanced data rates for GSM evolution (EDGE). OFDMA may be implemented by wireless technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, evolved UTRA (E-UTRA), and the like. IEEE 802.16m is an evolution of IEEE 802.16e and provides backward compatibility with systems based on IEEE 802.16e. UTRA is part of a universal mobile telecommunications system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is part of evolved UMTS (E-UMTS) using evolved-UMTS terrestrial radio access (E-UTRA), which employs OFDMA in downlink and SC in uplink -FDMA is adopted. LTE-A (advanced) is the evolution of 3GPP LTE.

For clarity, the following description focuses on LTE-A, but the technical spirit of the present invention is not limited thereto.

1 shows a wireless communication system to which the present invention is applied. This may also be called an Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN), or Long Term Evolution (LTE) / LTE-A system.

Referring to FIG. 1, the E-UTRAN includes at least one base station (BS) 20 that provides a control plane and a user plane to the terminal. The UE 10 may be fixed or mobile and may have other mobile stations, advanced MSs (AMS), user terminals (UTs), subscriber stations (SSs), wireless devices (Wireless Devices), and the like. It may be called a term.

The base station 20 generally refers to a station communicating with the terminal 10, and includes an evolved-NodeB (eNodeB), a Base Transceiver System (BTS), an Access Point, an femto-eNB, It may be called other terms such as a pico-eNB, a home eNB, and a relay. The base station 20 may provide at least one cell to the terminal. The cell may mean a geographic area where the base station 20 provides a communication service or may mean a specific frequency band. The cell may mean a downlink frequency resource and an uplink frequency resource. Alternatively, the cell may mean a combination of a downlink frequency resource and an optional uplink frequency resource. In addition, in general, when carrier aggregation (CA) is not considered, one cell always has a pair of uplink and downlink frequency resources.

An interface for transmitting user traffic or control traffic may be used between the base stations 20. The source base station (Source BS) 21 refers to a base station in which a radio bearer is currently set up with the terminal 10, and the target base station (Target BS, 22) means that the terminal 10 disconnects the radio bearer from the source base station 21 and renews it. It means a base station to be handed over to establish a radio bearer.

The base stations 20 may be connected to each other through an X2 interface, which is used to exchange messages between the base stations 20. The base station 20 is connected to an evolved packet system (EPS), more specifically, a mobility management entity (MME) / serving gateway (S-GW) 30 through an S1 interface. The S1 interface supports a many-to-many-relation between base station 20 and MME / S-GW 30. The PDN-GW 40 is used to provide packet data services to the MME / S-GW 30. The PDN-GW 40 varies depending on the purpose or service of communication, and the PDN-GW 40 supporting a specific service can be found using APN information.

Inter-E-UTRAN handover is a basic handover mechanism used for handover between E-UTRAN access networks. It is composed of X2 based handover and S1 based handover. The X2-based handover is used when the UE wants to handover from the source base station (source BS, 21) to the target base station (target BS, 22) using the X2 interface, where the MME / S-GW 30 is changed. It doesn't work. By S1 based handover, the first bearer set between the P-GW 40, the MME / S-GW 30, the source base station 21, and the terminal 10 is released, and the P-GW 40 is released. A new second bearer is established between the GW 40, the MME / S-GW 30, the target base station 22, and the terminal 10.

2 shows a network structure for MBMS to which the present invention is applied.

Referring to FIG. 2, a radio access network (EUTRAN) 200 includes a multi-cell coordination entity (hereinafter referred to as MCE, 210) and a base station (eNB) 220. The MCE 210 is a main entity controlling the MBMS, and serves as session management, radio resource allocation, or admission control of the base station 220 in the MBSFN region. . The MCE 210 may be implemented in the base station 220 or may be implemented independently of the base station 220. The interface between the MCE 210 and the base station 220 is called an M2 interface. The M2 interface is an internal control plane interface of the wireless access network 200, and MBMS control information is transmitted. If the MCE 210 is implemented in the base station 220, the M2 interface may only exist logically.

An Evolved Packet Core (EPC) 250 includes an MME 260 and an MBMS Gateway (MBMS GW) 270. MME 260 is NAS signaling, roaming, authentication (authentication), PDN gateway and S-GW selection, MME selection for handover by MME change, accessibility to the idle mode terminal, AS security Performs operations such as security control.

The MBMS gateway 270 is an entity that transmits MBMS service data and is located between the base station 220 and the BM-SC, and performs MBMS packet transmission and broadcast to the base station 220. The MBMS gateway 270 uses PDCP and IP multicast to transmit user data to the base station 220, and performs session control signaling for the radio access network 200.

The interface between the MME 260 and the MCE 210 is a control plane interface between the radio access network 200 and the EPC 250, which is called an M3 interface, and transmits control information related to MBMS session control. The MME 260 and the MCE 210 transmit session control signaling, such as a session start / stop message for session start or session stop, to the base station 220, The base station 220 may inform the terminal that the MBMS service is started or stopped through cell notification.

The interface between the base station 220 and the MBMS gateway 270 is an interface of a user plane, which is called an M1 interface, and transmits MBMS service data.

3 shows a user plane structure for MBMS support, and FIG. 4 shows a control plane structure for MBMS support.

Hereinafter, the RRC state and the RRC connection method of the UE will be described in detail.

The RRC state refers to whether or not the RRC layer of the UE is in a logical connection with the RRC layer of the E-UTRAN. If connected, the RRC connection state is called. Since the UE in the RRC connected state has an RRC connection, the E-UTRAN can grasp the existence of the corresponding UE in a cell unit, and thus can effectively control the UE. On the other hand, the UE of the RRC idle state cannot be understood by the E-UTRAN, and is managed by the CN (core network) in units of a tracking area, which is a larger area unit than the cell. That is, the UE in the RRC idle state is identified only in a large area unit, and must move to the RRC connected state in order to receive a normal mobile communication service such as voice or data.

When the user first powers on the terminal, the terminal first searches for an appropriate cell and then stays in an RRC idle state in the cell. When the UE in the RRC idle state needs to establish an RRC connection, it establishes an RRC connection with the E-UTRAN through an RRC connection procedure and transitions to the RRC connected state. There are several cases in which the UE in RRC idle state needs to establish an RRC connection. For example, an uplink data transmission is necessary due to a user's call attempt, or a paging message is sent from E-UTRAN. If received, a response message may be sent.

The non-access stratum (NAS) layer located above the RRC layer performs functions such as session management and mobility management.

In order to manage mobility of the UE in the NAS layer, two states of EMM-REGISTERED (EPS Mobility Management-REGISTERED) and EMM-DEREGISTERED are defined, and these two states are applied to the UE and the MME. The initial terminal is in the EMM-DEREGISTERED state, and the terminal performs a process of registering with the corresponding network through an initial attach procedure to access the network. If the attach procedure is successfully performed, the UE and the MME are in the EMM-REGISTERED state.

In order to manage a signaling connection between the UE and the EPC, two states are defined, an EPS Connection Management (ECM) -IDLE state and an ECM-CONNECTED state, and these two states are applied to the UE and the MME. When the UE in the ECM-IDLE state establishes an RRC connection with the E-UTRAN, the UE is in the ECM-CONNECTED state. The MME in the ECM-IDLE state becomes the ECM-CONNECTED state when it establishes an S1 connection with the E-UTRAN. When the terminal is in the ECM-IDLE state, the E-UTRAN does not have context information of the terminal. Accordingly, the UE in the ECM-IDLE state performs a terminal-based mobility related procedure such as cell selection or cell reselection without receiving a command from the network. On the other hand, when the terminal is in the ECM-CONNECTED state, the mobility of the terminal is managed by the command of the network. In the ECM-IDLE state, if the position of the terminal is different from the position known by the network, the terminal informs the network of the corresponding position of the terminal through a tracking area update procedure.

Next, system information will be described.

The system information includes essential information that the terminal needs to know in order to access the base station. Therefore, the terminal must receive all system information before accessing the base station, and must always have the latest system information. In addition, since the system information is information that all terminals in a cell should know, the base station periodically transmits the system information. System information is divided into a master information block (MIB) and a plurality of system information blocks (SIB).

The MIB may include a limited number of parameters, the most essential and most frequently transmitted, required to be obtained for other information from the cell. The terminal first finds the MIB after downlink synchronization. The MIB may include information such as downlink channel bandwidth, PHICH settings, SFNs that support synchronization and operate as timing criteria, and eNB transmit antenna settings. The MIB may be broadcast transmitted on a broadcast channel (BCH).

Among the included SIBs, SIB1 (SystemInformationBlockType1) is included in the "SystemInformationBlockType1" message and transmitted. Other SIBs except SIB1 are included in the system information message and transmitted. The mapping of the SIBs to the system information message may be flexibly set by the scheduling information list parameter included in the SIB1. However, each SIB is included in a single system information message, and only SIBs having the same scheduling request value (e.g. period) may be mapped to the same system information message. In addition, SIB2 (SystemInformationBlockType2) is always mapped to a system information message corresponding to the first entry in the system information message list of the scheduling information list. Multiple system information messages can be sent within the same period. SIB1 and all system information messages are sent on the DL-SCH.

In addition to the broadcast transmission, the E-UTRAN may be dedicated signaling while the SIB1 includes a parameter set equal to a previously set value, and in this case, the SIB1 may be transmitted by being included in an RRC connection reconfiguration message.

SIB1 includes information related to UE cell access and defines scheduling of other SIBs. SIB1 is used as PLMN identifiers of the network, tracking area code (TAC) and cell ID, cell barring status indicating whether the cell is a cell that can be camped on, and cell reselection criteria It may include information related to the lowest reception level required in the cell to be transmitted, and the transmission time and period of other SIBs.

SIB2 may include radio resource configuration information common to all terminals. SIB2 includes uplink carrier frequency and uplink channel bandwidth, RACH configuration, paging configuration, uplink power control configuration, sounding reference signal configuration, PUCCH configuration supporting ACK / NACK transmission, and It may include information related to the PUSCH configuration.

The UE may apply the acquisition and change detection procedure of the system information only to the primary cell (PCell). In a secondary cell (SCell), when the SCell is added, the E-UTRAN may provide all system information related to the RRC connection state operation through dedicated signaling. Upon changing the relevant system information of the established SCell, the E-UTRAN may release the SCell under consideration and add it later, which may be performed with a single RRC connection reset message. The E-UTRAN may set parameter values different from those broadcast in the SCell under consideration through dedicated signaling.

The terminal should guarantee the validity of the specific type of system information, and such system information is called required system information. Essential system information can be defined as follows.

When the UE is in the RRC idle state: The UE should ensure that it has valid versions of MIB and SIB1 as well as SIB2 to SIB8, which may be subject to the support of the considered radio access technology (RAT).

When the terminal is in the RRC connection state: The terminal should ensure that it has a valid version of MIB, SIB1 and SIB2.

In general, the system information can be guaranteed valid up to 3 hours after acquisition.

In general, services provided by a network to a terminal can be classified into three types as follows. In addition, the terminal also recognizes the cell type differently according to which service can be provided. The following describes the service type first, followed by the cell type.

1) Limited service: This service provides Emergency Call and Tsunami Warning System (ETWS) and can be provided in an acceptable cell.

2) Normal service: This service means a public use for general use, and can be provided in a suitable or normal cell.

3) Operator service: This service means service for network operator. This cell can be used only by network operator and not by general users.

In relation to the service type provided by the cell, the cell types may be classified as follows.

1) Acceptable cell (Acceptable cell): A cell in which the terminal can receive limited service. This cell is a cell that is not barred from the viewpoint of the terminal and satisfies the cell selection criteria of the terminal.

2) Normal cell (Suitable cell): a cell in which the terminal can receive a regular service. This cell satisfies the conditions of an acceptable cell and at the same time satisfies additional conditions. As an additional condition, this cell must belong to a Public Land Mobile Network (PLMN) to which the terminal can access, and must be a cell which is not prohibited from performing a tracking area update procedure of the terminal. If the cell is a CSG cell, the terminal should be a cell that can be connected to the cell as a CSG member.

3) Barred cell: A cell that broadcasts information that a cell is a prohibited cell through system information.

4) Reserved cell: A cell that broadcasts information that a cell is a reserved cell through system information.

5 shows the operation of the terminal in the RRC idle state. FIG. 5 illustrates a procedure in which a terminal initially powered on registers with a network through a cell selection process and then reselects a cell if necessary.

Referring to FIG. 5, the terminal selects a radio access technology (RAT) for communicating with a public land mobile network (PLMN), which is a network to be serviced (S510). Information about the PLMN and the RAT may be selected by a user of the terminal or may be stored in a universal subscriber identity module (USIM).

The terminal selects a cell having the largest value among the cells whose measured signal strength or quality is greater than a specific value (Cell Selection) (S520). This is referred to as initial cell selection by the UE that is powered on to perform cell selection. The cell selection procedure will be described later. After cell selection, the terminal receives system information periodically transmitted by the base station. The above specific value refers to a value defined in the system in order to ensure the quality of the physical signal in data transmission / reception. Therefore, the value may vary depending on the RAT applied.

If there is a need for network registration, the terminal performs a network registration procedure (S530). The terminal registers its information (eg IMSI) in order to receive a service (eg paging) from the network. When the UE selects a cell, the UE does not register with the accessing network, and registers with the network when the network information (for example, Tracking Area Identity; TAI) received from the system information is different from the network information known to the network. Do it.

The terminal performs cell reselection based on the service environment provided by the cell or the environment of the terminal (S540). The terminal provides better signal characteristics than the cell of the base station to which the terminal is currently connected if the strength or quality of the signal measured from the base station (serving base station) currently being served is lower than the value measured from the base station of the neighboring cell. Select one of the other cells. This process is called Cell Re-Selection, which is distinguished from Initial Cell Selection of Step 2. At this time, in order to prevent the cell from being frequently reselected according to the change of the signal characteristic, a time constraint is placed. The cell reselection procedure will be described later.

6 shows a process of establishing an RRC connection.

The terminal sends an RRC connection request message to the network requesting an RRC connection (S610), and in this case, the terminal may be in an RRC idle state. In addition, when the RRC connection request message is sent to the network, the UE may start a timer, in which case the timer may be T300 of 3GPP TS 36.311. The network sends an RRC connection setup message in response to the RRC connection request (S620). After receiving the RRC connection configuration message, the terminal enters the RRC connection mode. In this case, the terminal may stop the timer started in step S510. The terminal sends an RRC connection setup complete message used to confirm successful completion of the RRC connection establishment to the network (S630).

7 shows an RRC connection resetting process.

RRC connection reconfiguration is used to modify an RRC connection. It is used to establish / modify / release RBs, perform handovers, and set up / modify / release measurements. The network sends an RRC connection reconfiguration message for modifying the RRC connection to the terminal (S710). In response to the RRC connection reconfiguration, the terminal sends an RRC connection reconfiguration complete message used to confirm successful completion of the RRC connection reconfiguration to the network (S720).

Hereinafter, a public land mobile network (PLMN) will be described.

PLMN is a network deployed and operated by mobile network operators. Each mobile network operator runs one or more PLMNs. Each PLMN may be identified by a mobile country code (MCC) and a mobile network code (MCC). The PLMN information of the cell is included in the system information and broadcasted.

In PLMN selection, cell selection and cell reselection, various types of PLMNs may be considered by the terminal.

Home PLMN (HPLMN): PLMN having MCC and MNC matching MCC and MNC of UE IMSI.

Equivalent HPLMN (EHPLMN): A PLMN that is equivalent to an HPLMN.

Registered PLMN (RPLMN): A PLMN that has successfully completed location registration.

Equivalent PLMN (EPLMN): A PLMN that is equivalent to an RPLMN.

Each mobile service consumer subscribes to HPLMN. When a general service is provided to a terminal by HPLMN or EHPLMN, the terminal is not in a roaming state. On the other hand, when a service is provided to a terminal by a PLMN other than HPLMN / EHPLMN, the terminal is in a roaming state, and the PLMN is called a VPLMN (Visited PLMN).

When the terminal is initially powered on, the terminal searches for an available public land mobile network (PLMN) and selects an appropriate PLMN for receiving a service. PLMN is a network deployed or operated by a mobile network operator. Each mobile network operator operates one or more PLMNs. Each PLMN may be identified by a mobile country code (MCC) and a mobile network code (MCC). The PLMN information of the cell is included in the system information and broadcasted. The terminal attempts to register the selected PLMN. If the registration is successful, the selected PLMN becomes a registered PLMN (RPLMN). The network may signal the PLMN list to the UE, which may consider PLMNs included in the PLMN list as PLMNs such as RPLMNs. The terminal registered in the network should be reachable by the network at all times. If the terminal is in the ECM-CONNECTED state (same as RRC connected state), the network recognizes that the terminal is receiving the service. However, when the terminal is in the ECM-IDLE state (same as the RRC idle state), the situation of the terminal is not valid in the eNB but is stored in the MME. In this case, the location of the UE in the ECM-IDLE state is known only to the MME as the granularity of the list of tracking areas (TAs). A single TA is identified by a tracking area identity (TAI) consisting of the PLMN identifier to which the TA belongs and a tracking area code (TAC) that uniquely represents the TA within the PLMN. Subsequently, the UE selects a cell having a signal quality and characteristics capable of receiving an appropriate service from among cells provided by the selected PLMN.

Next, a procedure of selecting a cell by the terminal will be described in detail.

When the power is turned on or staying in the cell, the terminal selects / reselects a cell of an appropriate quality and performs procedures for receiving a service. The UE in the RRC idle state should always select a cell of appropriate quality and prepare to receive service through this cell. For example, a terminal that has just been powered on must select a cell of appropriate quality to register with the network. When the terminal in the RRC connected state enters the RRC idle state, the terminal should select a cell to stay in the RRC idle state. As such, the process of selecting a cell satisfying a certain condition in order for the terminal to stay in a service standby state such as an RRC idle state is called cell selection. Importantly, since the cell selection is performed in a state in which the UE does not currently determine a cell to stay in the RRC idle state, it is most important to select the cell as soon as possible. Therefore, if the cell provides a radio signal quality of a predetermined criterion or more, even if this cell is not the cell providing the best radio signal quality to the terminal, it may be selected during the cell selection process of the terminal.

Now, referring to 3GPP TS 36.304 V8.5.0 (2009-03) "User Equipment (UE) procedures in idle mode (Release 8)", a method and procedure for selecting a cell by a UE in 3GPP LTE will be described in detail.

There are two main cell selection processes.

First, an initial cell selection process, in which the terminal does not have prior information on the radio channel. Accordingly, the terminal searches all radio channels to find an appropriate cell. In each channel, the terminal finds the strongest cell. Thereafter, the terminal selects a corresponding cell if it finds a suitable cell that satisfies a cell selection criterion.

Next, the terminal may select the cell by using the stored information or by using the information broadcast in the cell. Thus, cell selection can be faster than the initial cell selection process. The UE selects a corresponding cell if it finds a cell that satisfies a cell selection criterion. If a suitable cell that satisfies the cell selection criteria is not found through this process, the UE performs an initial cell selection process.

After the terminal selects a cell through a cell selection process, the strength or quality of a signal between the terminal and the base station may change due to a change in mobility or a wireless environment of the terminal. Therefore, if the quality of the selected cell is degraded, the terminal may select another cell that provides better quality. When reselecting a cell in this way, a cell that generally provides better signal quality than the currently selected cell is selected. This process is called cell reselection. The cell reselection process has a basic purpose in selecting a cell that generally provides the best quality to a terminal in view of the quality of a radio signal.

In addition to the quality of the wireless signal, the network may determine the priority for each frequency and notify the terminal. Upon receiving this priority, the UE considers this priority prior to the radio signal quality criteria in the cell reselection process.

As described above, there is a method of selecting or reselecting a cell according to a signal characteristic of a wireless environment.In selecting a cell for reselection when reselecting a cell, the following cell reselection is performed according to a cell's RAT and frequency characteristics. There may be a method of selection.

Intra-frequency cell reselection: Reselection of a cell having the same center-frequency as the RAT, such as a cell in which the UE is camping

Inter-frequency cell reselection: Reselects a cell having a center frequency different from that of the same RAT as the cell camping

Inter-RAT cell reselection: The UE reselects a cell using a RAT different from the camping RAT.

The principle of the cell reselection process is as follows.

First, the UE measures the quality of a serving cell and a neighboring cell for cell reselection.

Second, cell reselection is performed based on cell reselection criteria. The cell reselection criteria have the following characteristics with respect to serving cell and neighbor cell measurements.

Intra-frequency cell reselection is basically based on ranking. Ranking is an operation of defining index values for cell reselection evaluation and using the index values to order the cells in the order of the index values. The cell with the best indicator is often called the highest ranked cell. The cell indicator value is a value obtained by applying a frequency offset or a cell offset as necessary based on the value measured by the terminal for the corresponding cell.

Inter-frequency cell reselection is based on the frequency priority provided by the network. The terminal attempts to camp on the frequency with the highest frequency priority. The network may provide the priorities to be commonly applied to the terminals in the cell or provide the frequency priority through broadcast signaling, or may provide the priority for each frequency for each terminal through dedicated signaling. The cell reselection priority provided through broadcast signaling may be referred to as common priority, and the cell reselection priority set by the network for each terminal may be referred to as a dedicated priority. When the terminal receives the dedicated priority, the terminal may also receive a validity time associated with the dedicated priority. When the terminal receives the dedicated priority, the terminal starts a validity timer set to the valid time received together. The terminal applies the dedicated priority in the RRC idle mode while the validity timer is running. When the validity timer expires, the terminal discards the dedicated priority and applies the public priority again.

For inter-frequency cell reselection, the network may provide the UE with parameters (eg, frequency-specific offset) used for cell reselection for each frequency.

For intra-frequency cell reselection or inter-frequency cell reselection, the network may provide the UE with a neighboring cell list (NCL) used for cell reselection to the UE. This NCL contains cell-specific parameters (eg, cell-specific offsets) used for cell reselection.

For intra-frequency or inter-frequency cell reselection, the network may provide the UE with a cell reselection prohibition list (black list) used for cell reselection. The UE does not perform cell reselection for a cell included in the prohibition list.

Next, the ranking performed in the cell reselection evaluation process will be described.

The ranking criterion used to prioritize the cells is defined as in Equation 1.

Here, R _s is a ranking indicator of the serving cell, R _n is a ranking indicator of the neighbor cell, Q _{meas, s} is a quality value measured by the UE for the serving cell, Q _{meas, n} is a quality measured by the UE for the neighbor cell The value, Q _hyst, is a hysteresis value for ranking, and Q _offset is an offset between two cells.

In the intra-frequency, Q _offset = Q _{offsets, n} when the terminal receives an offset (Q _{offsets, n} ) between the serving cell and a neighbor cell _, and Q _offset = 0 when the terminal does not receive Q _{offsets, n} . .

In the inter-frequency, Q _offset = Q _{offsets, n} + Q _frequency when the terminal receives the offset (Q _{offsets, n} ) for the cell, and Q _offset = Q _frequency when the terminal does not receive the Q _{offsets, n} to be.

If the ranking index R _s of the serving cell and the ranking index R _n of the neighboring cell change in a similar state, the ranking ranking is constantly reversed so that the terminal may alternately select two cells. Q _hyst is a parameter for giving hysteresis in cell reselection to prevent the UE from reselecting two cells alternately.

The UE measures R _s of the serving cell and R _n of the neighbor cell according to the above equation, considers the cell having the highest ranking indicator value as the highest ranked cell, and reselects the cell.

According to the criteria, it can be seen that the quality of the cell serves as the most important criterion in cell reselection. If the reselected cell is not a regular cell, the terminal excludes the frequency or the corresponding cell from the cell reselection target.

The radio link failure will now be described.

The terminal continuously measures to maintain the quality of the radio link with the serving cell receiving the service. The terminal determines whether communication is impossible in the current situation due to deterioration of the quality of the radio link with the serving cell. If the quality of the serving cell is so low that communication is almost impossible, the terminal determines the current situation as a radio connection failure.

If a radio link failure is determined, the UE gives up maintaining communication with the current serving cell, selects a new cell through a cell selection (or cell reselection) procedure, and reestablishes an RRC connection to the new cell (RRC connection re). -establishment). In the specification of 3GPP LTE, normal communication is not possible and the following example is given.

-When the UE determines that there is a serious problem in the downlink communication quality based on the radio quality measurement result of the physical layer of the UE (when the PCell quality is determined to be low during the RLM)

When the random access procedure in the MAC sublayer continuously fails, it is determined that there is a problem in uplink transmission.

When the RLC sublayer determines that there is a problem in the uplink transmission because the uplink data transmission continuously fails.

If it is determined that the handover has failed.

When the message received by the terminal does not pass the integrity check.

Hereinafter, the RRC connection reestablishment procedure will be described in more detail.

8 shows an RRC connection reestablishment procedure.

Referring to FIG. 8, the UE suspends use of all radio bearers that are set except for Signaling Radio Bearer # 0 (SRB 0) and initializes various sublayers of an access stratum (AS) (S810). In addition, each sub-layer and the physical layer is set to a default configuration. During this process, the UE maintains an RRC connection state.

The UE performs a cell selection procedure for performing an RRC connection reconfiguration procedure (S820). The cell selection procedure of the RRC connection reestablishment procedure may be performed in the same manner as the cell selection procedure performed by the UE in the RRC idle state, although the UE maintains the RRC connection state. After performing the cell selection procedure, the UE checks the system information of the corresponding cell to determine whether the corresponding cell is a suitable cell (S830). If it is determined that the selected cell is an appropriate E-UTRAN cell, the UE transmits an RRC connection reestablishment request message to the cell (S840). On the other hand, if it is determined through the cell selection procedure for performing the RRC connection re-establishment procedure that the selected cell is a cell using a different RAT than E-UTRAN, the RRC connection re-establishment procedure is stopped, the terminal is in the RRC idle state Enter (S850).

The terminal may be implemented to complete the confirmation of the appropriateness of the cell within a limited time through the cell selection procedure and the reception of system information of the selected cell. To this end, the UE may drive a timer as the RRC connection reestablishment procedure is initiated. The timer may be stopped when it is determined that the terminal has selected a suitable cell. If the timer expires, the UE may consider that the RRC connection reestablishment procedure has failed and may enter the RRC idle state. This timer is referred to hereinafter as a radio link failure timer. In LTE specification TS 36.331, a timer named T311 may be used as a radio link failure timer. The terminal may obtain the setting value of this timer from the system information of the serving cell.

When the RRC connection reestablishment request message is received from the terminal and the request is accepted, the cell transmits an RRC connection reestablishment message to the terminal. Upon receiving the RRC connection reestablishment message from the cell, the UE reconfigures the PDCP sublayer and the RLC sublayer for SRB1. In addition, it recalculates various key values related to security setting and reconstructs the PDCP sublayer responsible for security with newly calculated security key values. Through this, SRB 1 between the UE and the cell is opened and an RRC control message can be exchanged. The terminal completes the resumption of SRB1 and transmits an RRC connection reestablishment complete message indicating that the RRC connection reestablishment procedure is completed to the cell (S860). On the contrary, if the RRC connection reestablishment request message is received from the terminal and the request is not accepted, the cell transmits an RRC connection reestablishment reject message to the terminal. If the RRC connection reestablishment procedure is successfully performed, the cell and the terminal performs the RRC connection reestablishment procedure. Through this, the UE recovers the state before performing the RRC connection reestablishment procedure and guarantees the continuity of the service to the maximum.

MBMS and MBSFN (multicast / broadcast single frequency network) will now be described in detail.

Transmission in MBSFN transmission or MBSFN mode refers to a simultaneous transmission scheme implemented by transmitting the same signal in a plurality of cells at the same time. MBSFN transmissions from a plurality of cells within the MBSFN area appear to the UE as a single transmission.

MBMS services can be managed or localized on a cell-based or geography-based basis. The MBMS service area is a general term for the area where a particular MBMS service is provided. For example, if an area where a specific MBMS service A is performed is called an MBMS service area A, the network may be in a state of transmitting an MBMS service A in the MBMS service area A. In this case, the terminal may receive the MBMS service A according to the capability of the terminal. The MBMS service area may be defined in terms of applications and services as to whether or not a particular service is provided in a certain area.

A logical channel multicast control channel (MCCH) or a multicast traffic channel (MTCH) may be mapped to a transport channel MCH for an MBMS. MCCH transmits MBMS related RRC message, and MTCH transmits traffic of specific MBMS service. There is one MCCH for each MBMS Single Frequency Network (MBSFN) region that transmits the same MBMS information / traffic. When a plurality of MBSFN regions are provided in one cell, the terminal may receive a plurality of MCCHs. The MCCH contains one MBSFN area setup RRC message and has a list of all MBMS services. When an MBMS-related RRC message is changed in a specific MCCH, a physical downlink control channel (PDCCH) transmits an MBMS Radio Network Temporary Identity (M-RNTI) and an indicator indicating a specific MCCH. The terminal supporting the MBMS may receive the M-RNTI and the MCCH indicator through the PDCCH, determine that the MBMS-related RRC message has been changed in the specific MCCH, and receive the specific MCCH. The RRC message of the MCCH may be changed at each modification period, and is repeatedly broadcasted at every repetition period. A notification mechanism is used to inform the change of the MCCH due to the presence of the MCCH session start or MBMS counting request message. The UE detects a known MCCH change through the MCCH monitoring in the change cycle, not by the notification mechanism. The MTCH is a logical channel carrying an MBMS service. When there are many services provided in the MBSFN area, a plurality of MTCHs may be configured.

The terminal may receive a dedicated service while receiving the MBMS service. For example, a user may watch a TV through an MBMS service through his own smartphone, and chat using an IM (instant messaging) service such as MSN or Skype using the smartphone. . In this case, the MBMS service is provided through MTCH received by several terminals together, and the service provided to each terminal individually, such as IM service, will be provided through a dedicated bearer such as DCCH or DTCH.

In one area, some base stations can use multiple frequencies at the same time. In this case, in order to efficiently use radio resources, the network may select one of a plurality of frequencies to provide an MBMS service only at that frequency and provide a dedicated bearer to each terminal at all frequencies. In this case, when a terminal that has received a service using a dedicated bearer at a frequency where the MBMS service is not provided, if the terminal wants to receive the MBMS service, the terminal should be handed over to the frequency where the MBMS is provided. To this end, the terminal transmits an MBMS interest indication to the base station. That is, when the terminal wants to receive the MBMS service, the terminal transmits an MBMS interest indication to the base station, and when the base station receives the instruction, the terminal recognizes that the terminal wants to receive the MBMS service, and the terminal receives the MBMS service frequency. Move to. The MBMS interest indicator refers to information that the terminal wants to receive the MBMS service, and additionally includes information on which frequency it wants to move to.

A terminal that wants to receive a specific MBMS service first grasps frequency information and broadcast time information provided with the specific service. If the MBMS service is already broadcasting or soon starts broadcasting, the terminal sets the highest priority of the frequency in which the MBMS service is provided. The UE moves to a cell providing the MBMS service and receives the MBMS service by performing a cell reselection procedure using the reset frequency priority information.

If the UE is receiving or is interested in receiving MBMS service and can receive the MBMS service while camped on the frequency at which the MBMS service is provided, the reselected cell is SIB13 (System Information Block 13; System Information). In the case of broadcasting block 13), it may be considered that the highest priority was applied to the corresponding frequency during the MBMS session as long as the following situation persists.

When indicated by SIB15 of the serving cell that one or more MBMS Service Area Identities (SAIs) are included in the User Service Description (USD) of the service.

SIB15 is not broadcasted in the serving cell and its frequency is included in the USD of the service.

The UE should be able to receive MBMS in RRC_IDLE and RRC_CONNECTED states.

In the RRC_IDLE state, the UE may operate as follows. 1) UE-specific DRX may be configured by a higher layer. 2) The terminal monitors the paging channel to detect a call, system information change, ETWS notification, etc., and performs neighbor cell measurement and cell selection (reselection). The terminal may acquire system information and perform possible measurements.

In the RRC_CONNECTED state, the UE transmits unicast data, and UE-specific DRX may be configured in a lower layer. The terminal supporting the CA may use one or more secondary cells together with the primary cell.

The terminal monitors the paging channel and monitors the SIB1 contents in order to detect system information change. Monitor control channels associated with the shared data channel to determine if the data is scheduled for it. It also provides channel quality and feedback information. The terminal may measure the neighbor cell, report the measurement result, and obtain system information.

9 shows the structure of an MBSFN subframe.

Referring to FIG. 9, MBSFN transmission is set in subframe units. A subframe configured to perform MBSFN transmission is called an MBSFN subframe. In the subframe configured as the MBSFN subframe, MBSFN transmission is performed on the remaining OFDM symbols except for the first two OFDM symbols for PDCCH transmission. The area used for MBSFN transmission is referred to as an MBSFN area for convenience. Then, in the MBSFN region, the CRS for unicast is not transmitted, and the MBMS dedicated RS common to all cells participating in the transmission is used.

In order to inform the UE that does not receive the MBMS, the CRS is not transmitted in the MBSFN area, and broadcasts the configuration information of the MBSFN subframe in the system information of the cell. Since most terminals perform radio resource management (RRM), radio link failure (RLF) processing, and synchronization using the CRS, it is important to inform that the CRS is not in a specific region. The CRS is transmitted in the first two OFDM symbols used as the PDCCH in the MBSFN subframe, and this CRS is not for MBSFN use. In the first two OFDM symbols used as the PDCCH in the MBSFN subframe, the CP of the CRS transmitted (that is, whether the CRS uses a normal CP or an extended CP) is a normal subframe, that is, a subframe other than the MBSFN subframe Follow the CP applied in the frame. For example, when the general CP is used in the general subframe 911, the CRS according to the general CP is also used in the first two OFDM symbols 912 of the MBSFN subframe.

Meanwhile, subframes that can be configured as MBSFN subframes are designated for FDD and TDD, respectively, and can indicate whether or not they are MBSFN subframes through a bitmap. That is, if a bit corresponding to a specific subframe is 1 in the bitmap, the specific subframe is set to the MBSFN subframe.

10 shows an example of an MBSFN subframe configuration for performing an MBMS service.

Referring to FIG. 10, the UE acquires MBSFN subframe configuration information, MBSFN notification configuration information, and MBSFN area information list to perform MBMS service.

The UE may know the MBSFN subframe configuration information, that is, the location of the MBSFN subframe through SIB2 and RRC dedicated signaling. For example, the MBSFN subframe configuration information may be included in an MBSFN-SubframeConfig information element (IE).

In addition, the UE may acquire MBSFN region information list and MBMS notification configuration information as information necessary for obtaining MBMS control information associated with one or more MBSFN regions capable of performing MBMS service through SIB13. The MBSFN region information list includes MBSFN region ID for each MBSFN region, MBSFN region information in MBSFN subframe in MBSFN region, MBSFN subframe position where MCCH transmission is performed, and MBMS control information channel. May contain information. For example, the MBSFN area information list may be included in the MBSFN-AreaInfoList information element. On the other hand, MBSFN notification configuration information is the configuration information for the subframe location in which the MBMS notification that informs that there is a change in the MBSFN region configuration information transmitted to the terminal through the MCCH. For example, the MBSFN notification configuration information may be included in the MBMS-NotificationConfig information element. The MBSFN notification configuration information includes time information used for change notification of the MCCH applicable to all MBSFN regions. For example, the time information may include a notification repetition coefficient (notificationRepetitionCoeff), a notification offset (notificationOffset) and a notification subframe index (notificationSF-Index). Here, the notification repetition coefficient means a common change notification repetition period for all MCCHs. The notification offset indicates an offset of a radio frame for which MCCH change notification information is scheduled. The notification subframe index is a subframe index used for transmitting the MCCH change notification on the PDCCH.

The UE may obtain MBSFN region configuration information through the MCCH corresponding to each of the MBSFN regions obtained through SIB13. The MBSFN region configuration information may be included in the MBSFNAreaconfiguration message, and includes information on physical multicast channels (PMCHs) used by the corresponding MBSFN region. For example, the information on each PMCH includes the location of the MBSFN subframe in which the PMCH is located, Modulation and Coding Scheme (MCS) level information used for data transmission in the subframe, and MBMS service information transmitted by the PMCH. It may include.

UE receives MCH data through MTCH based on PMCH. Scheduling in time for the corresponding MCH data can be known through MSI (MCH Scheduling Information) coming down through PMCH. The MSI contains information about how long the MCH data transmission lasts.

11 illustrates a method of notifying the terminal of the change of MCCH information when the MCCH information is changed.

Referring to FIG. 11, a change of MCCH information occurring only in a specific radio frame may occur. The same MCCH information may be transmitted several times with the MCCH repetition period 1140 within the MCCH change period 1120. The indication of the MBMS-specific RNTI (M-RNTI) in the PDCCH may be used to inform the UE in the RRC_IDLE state and the change of the MCCH information to the UE in the RRC_CONNECTED state. The MCCH information change notification 1100 in the PDCCH may be periodically transmitted and may be transmitted in an MBSFN subframe. The MBMS capable RRC_IDLE terminal or the RRC_CONNECTED terminal may acquire MCCH information.

Hereinafter, a method and a problem of instructing to stop MBMS service through MCCH will be described.

The current terminal may recognize that the MBMS service is interrupted by a Temporary Mobile Group Identity (TMGI) through the MCCH. That is, if TMGI is not recognized, it can be known that MBMS service is stopped. However, the current method of recognizing the interruption of the MBMS service using TMGI may take a long time to inform the UE of the interruption of the MBMS service, which may cause the interruption of the service during the period. If the network decides to suspend and resume the MBMS service, the network transmits an MCCH change notification and updates the MCCH information, and then the UE recognizes that the MBMS service is stopped or started through the MCCH, as discussed in FIG. This is because, if the information is changed, a certain period must elapse to update the terminal. The method of recognizing whether the MBMS service is suspended or resumed through the MCCH is useful in that it does not require additional influence on the RAN2 specification, but may cause the service to be interrupted for a period of time. Therefore, new signaling can be used to recognize whether the MBMS service is suspended or resumed. The new signaling may be a special value in the MSI.

This will be described in detail with reference to 3GPP TS 36.321 V12.5.0 (2015-03).

12 shows the expanded MSI.

12- (a) shows an existing MSI (MCH Scheduling Information), Figure 12- (b) shows an extended MSI (MCH Scheduling Information). 12- (b), it can be seen that the S field S1201 is newly defined as compared with the MSI of FIG. 12- (a). In 3GPP TS 36.321 V12.5.0 (2015-03), the S field has been defined to indicate that transmission of the corresponding MTCH will be stopped. In the present invention, the S field may be called a special value in the MSI.

In consideration of the new signaling S field, the UE may stop the MBMS service by recognizing that the special value is included in the MSI. That is, when the network corresponding to the MBMS bearer is interrupted, the UE can quickly request the establishment of a unicast bearer to the network, and thus, between the termination of the MBMS bearer and the start of the unicast bearer as compared to the case of using TMGI over the MCCH. The gap can be further reduced. However, it is not clear whether stopping the MBMS service by using the special value of MSI means Stop or Suspension. The operation of the terminal to be performed will be described in detail.

In the present invention, the stop (Stop) is defined as to stop the MBMS service and release the MRB to not consider whether to resume the MBMS service afterwards, Suspension (Suspension) to stop the MBMS service, but the MBMS service will be resumed after It is defined as not to release the MRB in consideration.

First, a method of indicating MBMS service stop using MSI according to an embodiment of the present invention is proposed. That is, the terminal considers the special value only in the MBMS service interruption to the MSI and does not consider whether to resume the MBMS service afterwards.

The terminal may receive the MSI from the network. The terminal may stop the MBMS service if the received MSI includes a special value of the MSI. Thus, the UE does not need to receive the corresponding MSI / MTCH (and possibly the corresponding MCCH) and releases the corresponding MRB. On the other hand, the terminal establishes a corresponding unicast bearer. If the MBMS service is provided by the unicast bearer, the terminal will not need to monitor the current MSI / MTCH / MCCH to stop the MBMS service.

It is not necessary to prioritize the MBMS frequency of interest unless the RRC_IDLE state UEs stop the MBMS service by receiving the special value of the MSI and then consider whether to resume the MBMS service. If the RRC_CONNECTED state UEs stop the MBMS service by receiving the special value of the MSI and do not consider whether to resume the MBMS service thereafter, then the UE needs to indicate that it is not interested in the MBMSInterestIndication message. As described above, the proposal that the terminal stops the MBMS service using the MSI may be referred to as the operation of the new terminal as compared with the existing terminal operation that does not consider the MSI for service continuity.

Next, a method of indicating a suspension of an MBMS service using an MSI according to another embodiment of the present invention is proposed. That is, the terminal may consider the special value of the MSI to suspend the MBMS service and then resume the MBMS service.

The terminal may receive the MSI from the network. The terminal may suspend the MBMS service if the received MSI includes a special value of the MSI. In this case, since the network can resume the MTCH transmission of the MBMS service even after receiving the special value of the MSI, the terminal needs to continue monitoring the transmission after the MSI. That is, while the corresponding unicast bearer is established, the terminal should continue to perform the MBMS procedure without releasing the MRB. The terminal may continue to monitor the MSI, MTCH or MCCH, and if the MSI, MTCH or MCCH is monitored, the MBMS service may be resumed through the MRB. To this end, even though the UE establishes a unicast bearer after receiving the special value of MSI, it should be on the MBMS frequency and continue to prioritize the MBMS frequency of interest.

FIG. 13 is a block diagram illustrating a case in which a special value of an MSI is considered for MBMS service stop or suspension in accordance with an embodiment of the present invention.

The terminal may receive Multicast Channel Scheduling Information (MSI) from the network (S1310). The terminal may check whether a special value is included in the received MSI (S1320). If the special value is included, the terminal may determine whether to stop or suspend the MBMS service in consideration of the MBMS service interruption (S1330). The stop may be a stop not considering resumption of the MBMS service, and the suspension may be a stop considering a resume of the MBMS service.

If the interruption is a stop that does not consider resumption of the MBMS service, the terminal may release an MRB (radio bearer for MBMS). The terminal may stop monitoring the MSI, MTCH or MCCH. If the UE is in the RRC_IDLE state, it may stop prioritizing the MBMS frequency of interest, and if the UE establishes a unicast bearer and transitions to the RRC_CONNECTED state, it may indicate that there is no interest in the MBMSInterestIndication message.

If the interruption is a suspension considering the resumption of the MBMS service, the UE may maintain the MRB without releasing the MRB. The terminal may continue to monitor the MSI, MTCH or MCCH. If at least one of the MSI, MTCH, or MCCH is monitored, the terminal may resume the MBMS service suspended through the MRB. For this purpose, the terminal may continue to prioritize the MBMS frequency of interest. Even if the UE establishes a unicast bearer, the MRB may not be released.

14 is a diagram illustrating a wireless communication system in which an embodiment of the present invention is implemented.

The base station 1400 includes a processor 1401, a memory 1402, and a transceiver 1403. The memory 1402 is connected to the processor 1401, and stores various information for driving the processor 1401. The transceiver 1403 is connected to the processor 1401 and transmits and / or receives a radio signal. The processor 1401 implements the proposed functions, processes, and / or methods. In the above-described embodiment, the operation of the base station may be implemented by the processor 1401.

The terminal 1410 includes a processor 1411, a memory 1412, and a transceiver 1413. The memory 1412 is connected to the processor 1411 and stores various information for driving the processor 1411. The transceiver 1413 is coupled to the processor 1411 to transmit and / or receive wireless signals. The processor 1411 implements the proposed functions, processes and / or methods. In the above-described embodiment, the operation of the terminal may be implemented by the processor 1411.

The processor may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, and / or data processing devices. The memory may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium and / or other storage device. The transceiver may include baseband circuitry for processing wireless signals. When the embodiment is implemented in software, the above-described technique may be implemented as a module (process, function, etc.) for performing the above-described function. The module may be stored in memory and executed by a processor. The memory may be internal or external to the processor and may be coupled to the processor by various well known means.

Based on the examples described above, various techniques in accordance with the present disclosure have been described with reference to the drawings and reference numerals. For convenience of description, each technique described a number of steps or blocks in a specific order, but the specific order of these steps or blocks does not limit the invention described in the claims, and each step or block may be implemented in a different order, or In other words, it is possible to be performed simultaneously with other steps or blocks. In addition, it will be apparent to those skilled in the art that the steps or blocks have not been described in detail, and that at least one other step may be added or deleted without departing from the scope of the invention.

The above-described embodiments include various examples. Those skilled in the art will appreciate that not all possible combinations of examples of the inventions can be described, and that various combinations can be derived from the description herein. Therefore, the protection scope of the invention should be judged by combining various examples described in the detailed description within the scope of the claims described below.

Claims (15)

1. In the method for the terminal to stop and resume the MBMS service in a wireless communication system,

   Receive Multicast Channel Scheduling Information (MSI),

   Check whether the received MSI contains a special value,

   If the MSI includes the special value, including whether to stop (Stop) or Suspension (Suspension) of the MBMS service,

   The interruption of the MBMS service is an interruption of the MBMS service that does not consider resumption of the MBMS service.

   The suspension of the MBMS service is a suspension of the MBMS service considering the resumption of the MBMS service.
2. The method of claim 1,

   If it is decided to stop the MBMS service,

   The terminal further comprises releasing an MRB (radio bearer for MBMS).
3. The method of claim 2,

   The terminal further comprises stopping the monitoring of the MSI, MTCH or MCCH.
4. The method of claim 2,

   If the terminal is in the RRC_IDLE state, further comprising prioritizing the MBMS frequency of interest.
5. The method of claim 2,

   The terminal further comprises establishing a unicast bearer.
6. The method of claim 5, wherein

   The terminal further comprises indicating that no interest in the MBMSInterestIndication message.
7. The method of claim 1,

   If the decision to suspend the MBMS service,

   The terminal further comprises maintaining an MRB (radio bearer for MBMS).
8. The method of claim 7, wherein

   The terminal further comprises continuing to monitor the MSI, MTCH or MCCH.
9. The method of claim 8,

   If at least one of the MSI or the MTCH is monitored, resuming the suspended MBMS service through the MRB.
10. The method of claim 7, wherein

    The terminal further comprising continuing to prioritize the MBMS frequency of interest.
11. The method of claim 7, wherein

    The terminal further comprises establishing a unicast bearer.
12. A terminal for stopping and resuming an MBMS service in a wireless communication system,

    Memory; Transceiver; And a processor connecting the memory and the transceiver, wherein the processor

    Control the transceiver to receive Multicast Channel Scheduling Information (MSI),

    Check whether the received MSI contains a special value,

    If the MSI includes the special value, it is configured to determine whether to stop (Stop) or Suspension of the MBMS service,

    The interruption of the MBMS service is an interruption of the MBMS service that does not consider resumption of the MBMS service.

    The suspension of the MBMS service is characterized in that the suspension of the MBMS service considering the resumption of the MBMS service.
13. 13. The system of claim 12, wherein the processor is

    If it is decided to stop the MBMS service,

    And a terminal configured to release an MRB (radio bearer for MBMS).
14. 13. The system of claim 12, wherein the processor is

    If the decision to suspend the MBMS service,

    And a terminal configured to maintain an MRB (radio bearer for MBMS).
15. 15. The system of claim 14, wherein the processor is

    The terminal, characterized in that configured to continue to monitor the MSI, MTCH or MCCH.

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